Slightly extended transcription of the line in question, for those away from book:

Spoiler: Start of Darkness
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Redcloak: My Plan is for the betterment of the goblin people!

Right-Eye: You don't even KNOW the goblin people. Do you think this is what they want? To be ruled by an insane lich? To be killed by poor planning, or mood swings?

Redcloak: Look, I've spent my entire life—

Right-Eye: Your life? Your LIFE?? Brother, you may have had a lifetime, but you haven't had a life since the day you put on that cloak. Life is about growing—growing older, growing wiser, growing closer to your loved ones. But you, you're frozen in time. You're the same angry kid who took that artifact off of your master's corpse that day.

Redcloak: Oh, so now you've gained some great insight on the universe by letting your body and mind deteriorate?

Right-Eye: YES! When you're faced with your own mortality, you have no choice but to consider what's best for the next generation. And this deal with Xykon is killing our spirit almost as fast as it's killing our bodies. You don't even know what it is you're trying to better, because you don't know what it's like not to serve an undead overlord, or a petty spiteful god.


It's interesting that Right-Eye explicitly does link physical aging and decay with a concept of insight and growth. Mortality, and the awareness of it, is a fundamental aspect of life as Right-Eye has come to understand it, and Redcloak's eternal youth flies in the face of that.